The following volume attributes determine the services and characteristics of an NSS volume:
Encrypted volume support is provided for NSS volumes in NetWare 6.5 Support Pack 2 and later. It is available on OES SP1 Linux and later.
The Encryption attribute enables password-protected activation of encrypted NSS volumes. Encryption can be activated at creation time only, and this choice persists for the life of the volume. The sys: volume cannot be encrypted.
Use NSSMU to create encrypted volumes because the Encrypted attribute is currently not available when you create an NSS volume with iManager. For information, see Managing Encrypted NSS Volumes.
Volume attributes that can be set at volume-creation time include the following:
The Data Shredding attribute allows you to electronically overwrite deleted and purged data areas to prevent unauthorized users from using a disk editor to access purged files. You can specify the number of times (1 to 7) to shred data. For information, see Section 15.2, Using Data Shredding to Prevent Access to Deleted Files.
The Compression attribute activates file compression in NSS volumes. Compression can be activated at creation time only and this choice persists for the life of the volume. Data in the volume might be stored normally or in compressed form, depending on how frequently it is used. Compression parameters can be set at the server level to control compression behavior. For information, see Managing Compression on NSS Volumes.
The Data Migration attribute sets a flag that indicates to third-party software that this volume’s data can be migrated to near-line or offline storage media after it is inactive for specified lengths of time. This attribute requires third-party software to take advantage of the capability.
The Directory Quotas attribute enables you to assign a maximum quota of space that a directory can consume. For information, see Managing Space Quotas for Volumes, Directories, and Users.
The User Space Quotas (user space restrictions) attribute enables you assign a maximum quota of space that a user’s data can consume across all directories in the volume.
For information, see Managing Space Quotas for Volumes, Directories, and Users.
The Salvage Files attribute enables deleted files to remain on the volume until the Purge Delay time expires or until space is needed on the volume for other data. Until the Purge Delay time expires, the Salvage feature tracks the deleted files and allows the deleted files to be salvaged and restored. If space is needed, the oldest deleted files are purged to clear space.
If the Salvage Files attribute is disabled, deleted files are purged immediately on deletion.
For information, see Section 19.2, Configuring Salvage for the NSS Volume and Section 19.5, Salvaging or Purging Deleted Files.
The Lookup Name Space attribute sets the name space to use when you mount the volume. The name spaces are UNIX, Long, DOS, or Mac. For NSS volumes, the Long name space is highly recommended.
If you create an NSS volume on Linux, the name space defaults to UNIX, but you should consider choosing the Long names pace to improve performance, especially if you expect to store millions of files on the volume.
The Flush Files Immediately attribute enables NSS to immediately write to disk all data in cache that is pending writes to the file when you close the file. Otherwise, the data in cache must wait until the next write cycle to be written to the disk, putting the information at risk for loss during the interim, for example, if the server failed. For information, see Section 16.1, Using the Flush Files Immediately Attribute to Protect Against Possible Data Corruption on System Failure.
The User-Level Transaction Model enables the Transaction Tracking System™ (TTS™) function for this volume. TTS protects database applications by backing out transactions that are incomplete because of a system failure. For information, see Section 16.2, Using the Transaction Tracking System for Application-Based Transaction Rollback (NetWare).
The File-level Snapshot attribute enables a backup utility to capture the last closed version of a file that is open at the time a backup is in progress. You must manually deactivate the volume, then activate the volume after setting this attribute to let the volume set up the virtual volume for the metadata about file snapshots.
If the File Snapshot attribute is enabled, Novell Storage Management Services™ (SMS) saves the snapshot version of the file to backup media if a file is in use when the backup occurs. Some third-party backup applications can also take advantage of this attribute.
For more information, see Section 16.3, Using the File-Level Snapshot Attribute to Enable the Backup of Open Files.
The Modified File List (MFL) attribute enables NSS to create a list of all files modified since the previous backup. The log is available only through third-party software.
The Backup attribute sets a flag to indicate to the backup software that the volume contains data you want to back up. Disable this flag if the volume is empty or if backing up the data is unnecessary. This backup flag is independent of the third-party backup system you use; your backup system might not recognize this option, even if you select it.